LinkedList

LinkedListPlay.java

package cpsc5002_02;

public class LinkedListPlay {
	
	private static class Node {
		public double payload;
		public Node next;
		
		public Node(double payload, Node next) {
			this.payload = payload;
			this.next = next;
		}
	}
	
	private static Node head = null;

	public static void main(String[] args) {
		insertAtBeginning(100.6);
		insertAtBeginning(-14.1);
		insertAtBeginning(6.2);
		insertAtBeginning(7.8);
		insertAtBeginning(10000.6);
		insertAtBeginning(10.69);
		System.out.println("full list");
		printLinkedList();
		removeFromBeginning();
		System.out.println("one less");
		printLinkedList();
		removeFromBeginning();
		removeFromBeginning();
		removeFromBeginning();
		removeFromBeginning();
		removeFromBeginning();
		System.out.println("empty list");
		printLinkedList();
		removeFromBeginning();
		
		insertAtBeginning(1);
		insertAtBeginning(2);
		Node pred = head;
		insertAtBeginning(3);
		insertAtNode(pred,4);
		System.out.println("inserted in the middle");
		printLinkedList();
		removeAtNode(pred);
		System.out.println("deleted the 4 from the middle");
		printLinkedList();
	
	}
	
	private static void insertAtBeginning(double payload) {
		head = new Node(payload, head);
	}
	
	private static void removeFromBeginning() {
		if (head != null)
			head = head.next;
	}
	
	private static void insertAtNode(Node predecessor, double payload) {
		if (predecessor != null)
			predecessor.next = new Node(payload, predecessor.next);
	}
	
	private static void removeAtNode(Node predecessor) {
		if (predecessor != null)
			predecessor.next = predecessor.next.next;
	}
	
	private static void insertNth(int n, double payload) {
		if (n == 0) {
			insertAtBeginning(payload);
		} else {
			Node p = head;
			for (int i = 1; i < n; i++) {
				p = p.next;
				if (p == null)
					throw new IllegalArgumentException("list only has " + i + " nodes");
			}
			insertAtNode(p, payload);
		}
	}
	
	private static void printLinkedList() {
		for (Node q = head; q != null; q = q.next)
			System.out.println(q.payload);
	}

}